sfdisk -f $device >& /dev/null << EOF
$part1_offset,$part1_size,83,* //第一分区：从$part1_offset开始，$part1_size个柱面，LINUX_NATIVE (83)类型，启动分区
,$part2_size,L，- //第二分区：接着上一个分区，$part2_size个柱面，LINUX_NATIVE (83)类型，非启动分区
,,E //剩余空间为扩展分区 E is EXTENDED_PARTITION (5)
,,L //扩展分区全部划成逻辑分区
EOF
>& /dev/null : 重定向command 的stdout 到/dev/null
<< EOF EOF : list string
sfdisk : -f force
reads lines of the form : <start> <size> <id> <bootable> <c,h,s> <c,h,s>
Fields are separated by whitespace, or comma or semicolon possibly followed by whitespace; initial and trailing whitespace is ignored. Numbers can be octal, decimal or hexadecimal, decimal is default. When a field is absent or empty, a default value is used.
The <c,h,s> parts can (and probably should) be omitted - sfdisk computes them from <start> and <size> and the disk geometry as given by the kernel or specified using the -H, -S, -C flags.
Bootable is specified as [*|-], with as default not-bootable. (The value of this field is irrelevant for Linux - when Linux runs it has been booted already - but might play a role for certain boot loaders and for other operating systems. For example, when there are several primary DOS partitions, DOS assigns C: to the first among these that is bootable.)
Id is given in hex, without the 0x prefix, or is [E|S|L|X], where L (LINUX_NATIVE (83)) is the default, S is LINUX_SWAP (82), E is EXTENDED_PARTITION (5) , and X is LINUX_EXTENDED (85).
分区实例：
60 echo "[Partitioning $1...]"
61
62 DRIVE=$1
63 dd if=/dev/zero of=$DRIVE bs=1024 count=1024 &>/dev/null
64
65 SIZE=`fdisk -l $DRIVE | grep Disk | awk '{print $5}'` //检测多少字节
66
67 echo DISK SIZE - $SIZE bytes
68
69 CYLINDERS=`echo $SIZE/255/63/512 | bc` //计算多少柱面
70
71 echo CYLINDERS - $CYLINDERS
72 {
73 echo ,9,0x0C,*
74 echo ,$(expr $CYLINDERS / 4),,-
75 echo ,$(expr $CYLINDERS / 4),,-
76 echo ,,0x0C,-
77 } | sfdisk -D -H 255 -S 63 -C $CYLINDERS $DRIVE &> /dev/null //分区
。。。。。。。
86 mkfs.vfat -F 32 -n boot ${DRIVE}1 &> /dev/null //格式化
87 mkfs.ext4 -L rootfs ${DRIVE}2 &> /dev/null
88 mkfs.ext4 -L usrdata ${DRIVE}3 &> /dev/null
89 mkfs.vfat -F 32 -n data ${DRIVE}4 &> /dev/null